You can use StiftungSchweiz in German, English and French. If you are not logged in, you can select the language in the top right corner. If you are logged in and want to change your current language setting, select 'Account' in your user profile (avatar top right), select the desired language in the 'Language' drop-down menu and save your entry by clicking on 'Update'.
This allows you to customise the language in your 'Account'.